Sienna Miller and her boyfriend had "never" been on holiday together until a few months before she gave birth

Sienna - who also has 11-year-old daughter Marlowe with former partner Tom Sturridge - wrote in a piece for the Sunday Times Style magazine: "I was heftily pregnant when Oli and I decided to go for a week at the end of last year - when I was about 32 weeks, which was the last possible time, but that didn't stop me. I was lucky to have an easy pregnancy, so I was up for travelling far...

"When Oli and I were preparing for the trip we realised that we'd never actually been on holiday, just the two of us, in our entire relationship. So it was really magical to have that time together, thinking about each other and the baby that was about to arrive."

The 'Horizon: An American Saga' actress didn't want to just relax during her break.

She said: "I've got a very get-up-and-go attitude, so I didn't want to just lie around. We went swimming all the time and rode around on bicycles, which I think gave everyone a heart attack because I was enormous."

And Sienna and Oli got some guidance on how to approach her impending labour.

She explained: "As well as having the best massage of my life, we did a bespoke hypnobirthing course with a doula.

"It focused on how to manage labour together as a couple.

"I think men often go into new fatherhood with very little idea of how to manage the situation. They're just expected to understand, so it was nice to have some guidance.

"Our doula showed us the things Oli could do to support my birth and the pressure points and massage techniques that would help me.

"There was lots of looking in the eyes, holding hands and him stretching me. In quite a hippy way, which I love, it was a bonding celebration and way of connecting with the baby."